Suppose that there's a method of chemical castration that is 100% reversible and has no side effects except the total (temporary) loss of libido.
Some parents will want to administer it to their children until the age of 18. (If that's not sufficiently scary, let's compare it to Ritalin, and consider that schools will actively recommend to parents that problem kids be put on it.)
How many adults (especially politically credible square types) will be willing to publicly speak out against it?
Is there any way to stop it?
(Extra credit, even though you've probably already felt the answer: should it be stopped? Remember, it's not compulsory, no one's forcing it on you or your kids. It's something other people are choosing to give to their own minor children. Why would you feel like this is your business?)